Why aren't descriptive investigations repeatable

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

Substance a is a nonpolar liquid and has only dispersion forces among its constituent particles. substance b is also a nonpolar liquid and has about the same magnitude of dispersion forces among its constituent particles. when substance a and b are combined, they spontaneously mix.

A20 liter cylinder of helium at a pressure of 150 atm and a temperature of 27°c is used to fill a balloon at 1.00 atm and 37°c. what is the volume of the balloon? a. 0.14 liters b. 3000 liters c. 2900 liters d. 2400 liters e. 3100 liters